Solisphaeridium stimuliferum ssp. complanatum (W. Wetzel, 1952) Sarjeant, 1984

Originally Hystrichosphaeridium oligacanthum ssp. complanatum, subsequently
Baltisphaeridium oligacanthum ssp. complanatum (an acritarch subspecies), thirdly Cleistosphaeridium? oligacanthum ssp. complanatum, fourthly (and now) Solisphaeridium stimuliferum ssp. complanatum. Sarjeant, 1984 gave the citation
Solisphaeridium aff. stimuliferum ssp. complanatum and emended the subspecies at the time of the transfer.
Holotype: W. Wetzel, 1952, pl.A, figs.11a-b; Sarjeant, 1984, pl.4, fig.6; text-fig.13
Age: Paleocene